(a) Field of the Invention
The present invention relates to a method for transmitting signals and receiving signals in a multi-hop communication network.
This work was supported by the IT R&D program of MIC/IITA [2007-F-039-01, Vehicle Multi-hop Communication Technology Development].
(b) Description of the Related Art
WAVE (Wireless Access for Vehicle Environment) technique is IEEE (Institute of Electrical and Electronics Engineers) 802.11p wireless access technique for providing communication between a vehicle and base station or between vehicles.
The radio channel of the WAVE technique includes a control channel and a service channel.
The control channel is used for transmitting system control information or vehicle safe information, the service channel is used for transmitting user information, and the control channel and the service channel are allocated different frequency channels.
As described above, in order to allocate the control channel and service channel frequency separately in the WAVE technique, RF (Radio Frequency) channel switching is performed, thus there is the drawback of decreasing the time resource efficiency and increasing packet latency.
A wireless access protocol in the WAVE technique uses the CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) method.
The CSMA/CA method generates interference between terminals by contacting a plurality of terminal nodes simultaneously because of a Hidden Node, and there is the problem that the system latency increases remarkably according to increasing terminals because of the collision of wireless links.
Accordingly, the WAVE technique decreases the frequency resource efficiency and is a hard to provide system in real-time.
The above information disclosed in this Background section is only for enhancing the understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.